Earlier this summer, a pair of naturally mummified lion cubs were discovered in the permafrost of Northern Russia. Their bodies are so well preserved it's hard to believe that they're estimated to be over 10,000 years old. They belonged to an extinct relative of the modern lion known as Panthera leo spelaea and one of many pristine ancient animals that have recently been discovered in the melting permafrost, including an Oimyakon mammoth called Yuka, as well as bison, wooly rhinoceroses, and horses. Ancient Egyptians went to great lengths and elaborate rituals to mummify their royalty and wealthy upper-class, but mummification can occur naturally depending on the environment at the time of death. Under normal circumstances, when something dies, the bacteria in, on, and around it immediately begin to break it down. If everything goes as planned, within a few months all that's left is the creature's skeleton. But when bacteria are prevented from being able to do their jobs, and the organism dies and simply dries out.

This tends to happen in one of two different kind of environments: in cold, dry conditions when the body freezes before bacteria are able decompose the corpse, like in the case of Özti the Iceman, the oldest, most well-preserved human ever discovered. After dying under a rocky outcropping, he was quickly covered with snow, which created the perfect conditions for him to be mummified. A dry desert climate can cause mummification, too! Before they began mummifying their dead, early Egyptians buried dead in small pits. The high heat coupled with a lack of moisture caused dehydration and the corpses mummified naturally in a process called desiccation. The oldest man-made mummified bodies were found in the Atacama Desert in Chile. They're 6,500 years old and complete with wigs and mats. Although less common, mummies can also naturally form in peat bogs. A peat bog is a form of wetland that accumulates dead plant material called peat. The soil in them is acidic and low in nutrients which creates a very uninviting place for oxygen-based anaerobic bacteria. Bog mummies aren't as beautiful as those found frozen in glaciers or buried in deserts because the tissues aren't as well preserved.

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Ancient Cave Lion Cubs Found in Russian Permafrost (Discovery News)"The bodies of two extinct cave lion cubs from at least 10,000 years ago have been recovered in Russia's Sakha Republic, almost perfectly preserved in permafrost, The Siberian Times reports."

How Mummies Work (How Stuff Works)"The most familiar mummies, of course, are the carefully wrapped bodies of ancient Egypt. These figures are only one subsection of the world's mummy population, however. In the past 200 years, scientists, adventurers and capitalists have discovered ancient mummies in diverse locales all around the world."